# Star-formation in CALIFA early-type galaxies. A matter of discs

## TL;DR

This study reveals that star formation in early-type galaxies occurs exclusively in their disc components, which follow the star formation main sequence, while bulges show lower specific star formation rates, supporting a morphological quenching scenario.

## Contribution

First detailed analysis separating bulge and disc star formation in ETGs using spectro-photometric decomposition of IFU data.

## Key findings

- Star formation occurs only in discs, not bulges.
- Star-forming discs align with the star formation main sequence.
- Star formation is present at all radii, not just outskirts.

## Abstract

The star formation main sequence (SFMS) is a tight relation between the galaxy star formation rate (SFR) and its total stellar mass ($M_\star$). Early-type galaxies (ETGs) are often considered as low-SFR outliers of this relation. We study, for the first time, the separated distribution in the SFR vs. $M_\star$ of bulges and discs of 49 ETGs from the CALIFA survey. This is achieved using C2D, a new code to perform spectro-photometric decompositions of integral field spectroscopy datacubes. Our results reflect that: i) star formation always occurs in the disc component and not in bulges; ii) star-forming discs in our ETGs are compatible with the SFMS defined by star forming galaxies at $z \sim 0$; iii) the star formation is not confined to the outskirts of discs, but it is present at all radii (even where the bulge dominates the light); iv) for a given mass, bulges exhibit lower sSFR than discs at all radii; and v) we do not find a deficit of molecular gas in bulges with respect to discs for a given mass in our ETGs. We speculate our results favour a morphological quenching scenario for ETGs.